Convective Outlook: Mon 27 Jul 2020 |
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What do these risk levels mean? |
VALID 06:00 UTC Mon 27 Jul 2020 - 05:59 UTC Tue 28 Jul 2020
ISSUED 07:16 UTC Mon 27 Jul 2020
br> br>ISSUED BY: Dan
A deepening surface low will track northeast across Ireland, southern Scotland / northern England and out to the North Sea on Monday, beneath and to the north of a strong jet stream and on the forward side of a sharpening upper trough. Extensive cloud and outbreaks of rain are expected across many parts of the British Isles, given the high dewpoint airmass (14-17C) and rather saturated profiles. While some pockets of elevated convection, and hence a few isolated lightning strikes, will be possible embedded within broad areas of showery rain, the main focus during this forecast period will be close to the triple point and the area between the cold front and back-bent occlusion (which effectively acts as the true surface cold front, exhibiting the greatest dewpoint gradient and wind veer). Substantial forcing aloft combined with modest surface heating may be sufficient to generate some deep convection in an environment with 30-40kts bulk shear. Forecast profiles exhibit very moist low-levels overlain by marked dry air aloft, albeit with a slight warm nose in the ~600mb layer. If sufficient breaks in the cloud can allow insolation to lift surface temperatures to nearer 18-20C, then this may be able to pass the warm nose.